After experiencing multi-year droughts, officials in Atlanta estimated that running out of water could cost the city $100 million a day. To avoid those costs, the city took a proactive approach, creating a $300 million, 2.4-billion-gallon raw water storage facility in an abandoned quarry funded by a municipal-option sales tax. Using dynamite and a deep boring machine, the city has begun construction of the five-mile granite storage tunnel to be completed by the end of 2018. The project – creating one of America’s largest water reservoirs — will expand the city’s emergency water supply from three days to a month in the case of drought or contamination.